The present invention relates to a device for producing milk foam, in particular in connection with an automatic coffee machine, comprising a mixing chamber to which at least milk, air, and a rinsing medium can be supplied via various supply lines, wherein the supply of the rinsing medium to the mixing chamber takes place at least partially via the milk supply line.
The foaming of milk is required primarily in the making of cappuccino, but is also necessary for other purposes. In this process, milk is mixed with air and steam. A problem here is that the line segments charged with milk, in particular foamed milk, become clogged over time, because the milk dries onto these segments. In addition to the functional disturbances caused by this, these deposits also result in adverse sensory effects due to the congealed albumen and the breakdown of casein.
In order to avoid deposits of this sort, it is already known to regularly rinse the mixing chamber and the lines through which milk flows. Thus, for example in German patent application DE 199 55 195 A1 a coffee machine is described in which a rinsing medium (cold water or steam in the embodiment given there) is pumped both through the milk supply line and also directly into the mixing chamber. Here, the steam introduced directly into the mixing chamber can optionally be used to clean this chamber or to heat the milk during the preparation of drinks.
This known apparatus has proven successful in practice. The present invention is intended to further improve it with respect to its rinsing and cleaning effect. At the same time, the present invention should be distinguished by a high degree of functionality and an economical design.